Cereal starches and process



The present invention relates to removing undesirable taste fromcereal-starches and the products resulting therefrom. v v

' states-9 1m O lll this suspension; otherwise,

in the methanol and then aqueous ammonia was added to the procedure wassubstantially the same as that just described for ungelatinized starch.In all cases the starches treated in accordance with these exampleswerefree of cereal taste and remained so after aging forfour days at 104'F. and 85% relative humidity. The amount of-taste-producing materialextracted from the-starch fell within the range of l.0l.l% by weight ofthe starch.

Thcrfact that the starches of the examples in Table lhcrcinbcforcremaincd tree of oil-taste under the test con- 'lhcse werewet cakes, 2 500 grumsot starch was st The term taste" is used in the:specification and claims hereof to mean'tasterllavor, odor, eitheraloneor in any combination.- I

Although this invention is applicable toanystarch which contains anundesirable taste, it is especially applicable to wheatstarcnbccauseithas a verydecided undesirable (cereal) taste and terized by an odorwhich is quiteobjectionable uses. This oil-taste and cornv starch,torexample; in many food applications.

The taste producing substances are present, in the starch in both-theadsorbed andthc chemically-bound forms. Apparcntly'the priorartprcccsses at best remove only the adsorbed portion because even inthose cases in which the taste is removed it rapidly reappears.

for certai toncornfstarch because it is charachas precluded theuse ofwheat starch Thus the main object ofv the present invention is cereal Istarches fromwhich theoll-tastehas been permanently removedfandtheproeess of removing said taste. This and other objectswill'beapparent fromthe description of this invention given hereinafter.-

The above and other'objects are. accomplished according' to the presentinvention .by'carrying out the process which com-prises contactingcereal starch with an alcohol and aqueous -ammonia,.aand separatingthestareh-from the alcohol .and aqueous ammonia.

The following examples-illustrate specifieembodiments Of'thlsinventiom-but they are notintended to .limit'thc invention other thanasidefiried in, the claims of thisapplication. In the example-sand.elsewhere'hereinthe relative amountsol alcohol and aqueous ammoniatostarch used are expressed as milliliters of alcohol and-milliliters. ofaqueous-ammonia pergram of starch. In these examples a somewhatditlererit procedure was useddcpcnding on whether the starch wasgelatinized using ungelatinized starch {Examples 4-7), the starch wasslurricd in water with -agitation thev methanol and aqueous ammonia.were. added to thcislu-rry, the slurry was brought to the temperaturedcsiredand held at that temperature .for the desired time. the agitationbeing. continued throughout the-process. the slurry was then filtered,the filter cake washed with 'fresh methanol-aqueous ammonia mixture andthen with-water. Whenusing gelor ungelatinized. When 70 atiniz'ed starch(Examples l-3), the starch was suspended each containing about ltlOgrams of starch and 100 grams of water.

in this example because the uugclatlnizi-d dit'ions employed means that,from the standpoint of taste,

cereal starches treated in accordance with the present iuvention arequite adequate for any use, because these are highly acceleratedconditions as compared with the normal storage conditions (that is,atmospheric storage conditions). In fact, subjecting the starchestreated in accordance with this invention to these acceleratedconditions is equivalent to storingthese treated starches for severalmonths at atmospheric conditions.

The following two examples were carried out to determine the cllect ofusing an alcohol alone and using 28% aqueous ammonia alone.

Example 8 ALCOHOL IAIN l) Examples l-7 above were repeated except thatthe 23% aqueous ammonia and storage testing were omitted. All of thestarches so treated contained a decided oll-taste immediately aftertreatment, so there was no need to test them after storage.

Example 9 es o xomaous A.\L\lt)NlA. xnoxn Examples l-7 above wererepeated except that the anhydrous methanol and storage testing wereomitted. All of the starches so treated contained a decided oil-tasteimmediately after treatment, so there was no need to test them afterstorage.

Instead of. the 28% aqueous ammonia several other alkaline reagents weretriedunder substantially the same conditions-of the above examples. Inno case, however,

w-as the oil-taste removed. These other alkaline reagents includedanhydrous ammonia. urea. sodium hydroxide, potassium hydroxide, andsodium carbonate.

Althoughl do not wish to be restricted to any theory regarding thepossible mechanism of my invention there is-vcvidcncc that the oil-tastein cereal starches may be due to the presence oi lipids containingphosphorous or phosphatidcsr sec, c.g.. the article in American ChemicalSocicty Monograph Series No. ll2 (WSl), entitled The Phosphatidcs."written by ll. Wittcoll'. Apparently these lipids are associated in twodill'crcnt ways with all cereal starches, ice, adsorbed on the starchand also chemically bound to the starch molecule. Thus a successfulextraction. process ntust accomplish two goals; first, it mustcorlrltpletely dissolve and hydrolyze both the adsorbed and t echemically bound lipids, and secondly, it must solubilrze the extracted(i.e. the dissolved and hydrolyzed) lipids in the solvent system. I amaware that the prior art shows solvent extraction processes usingalcohols alone, using alcohols with acids or bases. and using alcoholswith both acids and bases. However, these processes have not beensuccessful and one explanation for this is based on the above theory.That is, those prior art processes using alcohols alone merely removethe adsorbed lipids so th the extracted starches are free of undesirabletastc only momentarily and soon after treatment the chemically houndlipids become hydrolyzed and oxidized in part to cause the regenerationof the undesirable taste. In the other prior art processes failure toremove the undesirable taste may have been caused by the solvent systembeing inadequate to soltlhilizc lipids so that they reprectpitatcd onthe starch. I

While from the standpoint of cost and availability methanol is the mostpractical solvent, l may use alcohols in general: provided, however.that they do not themselves contribute an undesirable taste to h o h othis basis I prefer to use the lower aliphatic alchols. c.g. those ofl-4 carbon atoms. The following alcohols. e.g., when substituted formethanol give quite satisfactory results in accordance with thisinvention: ethyl, n-propyl, isopropyl, I

n-butyl. isobutyl, secondary butyl, and tertiary butyl.

I obtain very good results using from 3/] to 8/1 ml. of methanol pergram of starch and using from to 1/] ml. of 28% aqueous ammonia per gramof starch. I

obtain even somewhat better results using 4 ml. of methanol per gram ofstarch in'combination with 0.5 ml. of I 28% aqueous ammonia per grant ofstarch.

Although the present invention is applicable to starch either before orafter gelatinization. the most practical stage at which to remove theobjectionable taste is the wetcake stage'during processing prior togelatinization. For instance, the wet cake treated in accordance withthis invention in the above examples was the starch taken from theconventional separators. which separate flour into starch and gluten,and centrifuged to 50%60% solids content prior to drying.

A considerable amount of deviation is permissible in the washing processdescribed above in the examples. Alcohol alone may be used instead ofthe alcohol-aqueous ammonia mixture. For the ungelatinized starches,water alone can be used. For the gelatinized starches, up to about 10%water can be tolerated in the wash alcohol. In still another verypractical way, the filtered, extracted wet cake is slurried in freshwater to the desired consistency and then dried directly.

As might be expected, time and temperature of the extracting treatmentvary inversely. I have obtained good results varying from about roomtemperature (25 (I.- 30 C.) for to hours to 65 C. for 2 hours.Conditions outside this range could he used, but usually they would notbe, justified.

This invention is applicable to any starch which contains an undesirabletaste, e.g.. wheat starch. corn starch, rice starch. ryc'starch, barleystarch, etc. Of these, this taste is perhaps more pronounced in wheatstarch and this invention may be made without departing from the spiritand scope thereof, it is to be understood that the 'fic embodimentsthereof invention not limited to the speci except as defined in theappended claims.

What I claim and desired to protect by Letters Patent 15. 1. Process ofremoving the undersirable taste front 10 cereal starches so that it doesno pp r 'WhtC h com;

prises contacting the starch with an alcohol and aqueotl ammonia, andseparating the starch from the alcohol n tteous ammonia.

2. Process of claim 1 wherein the alcohol is a lower r t atic alcohol.

1) g Process of claim 1 wherein the alcohol is methan l and wherein themethanol/starch and ammonia/starch ratios are 3/l-8/l and 0.5/l-l/l,respectively.

4. Process of claim 1 wherein the alcohol is methanol and wherein themethanol/starch and ammonia/starch ratios are 4/1 and 0.5/ l,respectively.

5. Process of claim 1 wherein the starch is wheat starch.

6. Process of claim] wherein the starch is corn starch.

7. Process of removing the undcrsirahle taste from gelatinized cerealstarches so that it does not reappear which comprises contacting thestarch with methanol and aqueous ammonia, separating the starch frontthe methanol and aqueous ammonia, and washing the starch with freshmethanol.

8. Process of removing the undersirable taste from ungelatinized cerealstarches so that it does not reappear which comprises contacting thestarch with methanol and aqueous ammonia and separating the starch fromthe methanol and aqueous ammonia and washing the starch with water.

9. In the process of separating cereal fiour into starch and gluten bywashing with water wherein the starch fraction is partially dewateredprior to drying, the improvement which comprises contacting thepartially dewatcred starch with an alcohol and aqueous ammonia, andseparating the starch front the alcohol and aqueous ammonia.

l0. Process of removing the undesirable taste from an tmgelatinizedcereal starch so that it does not reappear 15 which comprises contactingthe starch with methanol and aqueous ammonia. filtering, reslurrying thefiltered starch in fresh water and drying.

11. Process of claim 10 wherein the methanol/starch and theammonia/starch ratios are 3/1-8/1 and 0.5/l-

1/1, respectively.

References Cited in the file of this patent UNITED STATES PATENTS2,222,875 Leuck Nov. 26, 1940 2,280,723 Schoch Apr. 21, 1942 2,587,650Rist et al Mar. 4, 1952 'Radley: Starch and Its Derivatives, vol. II. p.339, 1954, 3rd Ed., Wiley & Sorts, New York, N.Y.

1. PROCESS OF REMOVING THE UNDERSIRABLE TASTE FROM CEREAL STARCHES SOTHAT IT DOES NOT REAPPER WHICH COMPRISES CONTACTING THE STARCH WITH ANALCOHOL AND AQUEOUS AMMONIA, AND SEPARATING THE STARCH FROM THE ALCOHOLAND AQUEOUS AMMONIA.